For the most part, there's little mystery as to what is in our homes. We put most of it there ourselves and even if we didn't get an explanation on weird features that came with the house, we eventually figured out what they did.
But every now and then, we can come across something with a purpose and origin that completely eludes us. It may have always been there or it may have ended up on the premises overnight. And if it's laying in a place that nobody has access to, it could be a loose part that fell off something.
In any case, but especially that last one, it's something that should be identified. And fortunately for the confused and curious among us, the r/whatisthisthing subreddit serves exactly that purpose.
And as we're about to see, its users do so pretty effectively.